<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>3</title>
	<script>
	// 3.接收用户输入的正整数，判断是否是5的倍数，并输出相应的结果
	var num=Number(prompt('输入正整数'));
	
	if (num<=0||parseInt(num)!==num) {
		console.log('请输入正整数');
	}else if(num%5==0){
		console.log(num+'是5的倍数');
	}
	else{
console.log(num+'不是5的倍数')
	}
	</script>
</head>
<body>
	
</body>
</html>